AssertionError for rows with zero columns

Details

Description

After upgrading from 1.2.5 to 1.2.9 and then to 2.0.2 we've got those exceptions:

ERROR [FlushWriter:1] 2013-11-18 16:14:36,305 CassandraDaemon.java (line 187) Exception in thread Thread[FlushWriter:1,5,main]
java.lang.AssertionError
at org.apache.cassandra.io.sstable.SSTableWriter.rawAppend(SSTableWriter.java:198)
at org.apache.cassandra.io.sstable.SSTableWriter.append(SSTableWriter.java:186)
at org.apache.cassandra.db.Memtable$FlushRunnable.writeSortedContents(Memtable.java:360)
at org.apache.cassandra.db.Memtable$FlushRunnable.runWith(Memtable.java:315)
at org.apache.cassandra.io.util.DiskAwareRunnable.runMayThrow(DiskAwareRunnable.java:48)
at org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)